Headbox for paper-making machine



June 7, 1966 s. M. SALOMON ETAL 3,255,074

HEADBOX FOR PAPER-MAKING MACHINE Filed April 5, 1964 6 Sheets-Sheet l EI7/ q AI m 5/ J/d z IN VEN TORG 4 @01220/2 1% 6ala%a12 BY M $4A%ATTORNEYSJune 7, 1966 Filed April 5, 1964 s. M. SALOMON ETAL 3,255,074

HEADBOX FOR PAPER-MAKING MACHINE 6 Sheets-Sheet 2 By X,

I XVEN TORS 6240/ /01/ /./6240M0/1/ 442 J /z/sras' #ATTORNEYS s. M.SALOMON ETAL 3,255,074

HEADBOX FOR PAPER-MAKING MACHINE June 7, 1966 6 Sheets-Sheet 5 FiledApril 5, 1964 @4/ d dzz iae' BY i M%IAZMWATTORNEYS June 7, 1966 5. MSALOMON ETAL HEADBOX FOR PAPER-MAKING MACHINE 6 Sheets-Sheet 4 FiledApril 5, 1964 M a m INVENTORii fi e/012204 ZSQZGMQ/Z Zafyw (f dz'zazw Biw ATTORNEYS June 7, 1966 s. M. SALOMON ETAL 3,

HEADBOX FOR PAPER-MAKING MACHINE Filed April 5, 1964 6 Sheets-Sheet 5 INVENTORL) 6&(0122912 ZZ 62/04/220 Z afya/ z/ wizza BY ATTORNEYS June 7,1966 s. M. SALOMON ETAL 3,255,074

HEADBOX FOR PAPER-MAKING MACHINE 6 Sheets-Sheet 6 INVENTOKS a/amazz 1/azzzazz Zafya/ d wezae' 12 z w ATTORNEYS United States Patent 3,255,074HEADBOX FOR PAPER-MAKING MACHINE Salomon M. Salomon and Edgar I; Justus,Beioit, Wis.,

assignors to Beloit Corporation, Beloit, Wis, acorporation of WisconsinFiled Apr. 3, 1964, Ser. No. 357,171 8 Claims. (Cl. 162-338) This is acontinuation-in-part of our applications Serial Nos. 140,350, filedSeptember 25, 1961 and 141,270, filed September 26, 1961, saidapplications now having been abandoned.

This invention relates to papermaking and like processes, and is moreparticularly directed to improved methods and means for minimizingflocculating of furnish immediately prior to its discharge from a flowchamber or headbox.

In the prior art, it is generally recognized that the condition of thefurnish or stock as it flows through the slice onto the forming surfaceof a papermaking machine is a critical factor in the determination ofthe characteristics of the forming web and the formed paper product.

Heretofore, many attempts have been made to condition the furnish priorto its delivery from the outlet onto the forming wire by rotary rollsand the like through which the stock passes for enhancing fiberdistribution and minimizing fioccing in the headbox. However, rotaryrectifier rolls or holey rolls are expensive, must be maintained insmooth, unscarred and uncorroded condition; otherwise they will fail toperform their function or produce even greater flocs, strings or lumpswhich may be released with the flow from the slice.

With the present invention, we substantially overcome the problems anddifiiculties of the prior art and provide eflicient means which areself-cleaning for dispersing fibers adjacent the outlet of a flowchannel or headboX.

It is therefore an object of the present invention to minimize floccingof papermaking stock and the like.

It is another object of the present invention to provide improved meansfor dispersing fibers in paperrnaking stock or furnish and the like.

Still another object of the present invention is to provide improvedmeans which are self-cleaning for minimizing fioccing of papermakingstock adjacent the outlet of the flow channel or headbox.

A further object of the present invention is to provide a hydrofoil andscreen arrangement for dispersing fibers in papermaking stock and thelike prior to delivery of the furnish to the forming surface of apapermaking machine.

Yet another object of the present invention is to provide improvedmethod for dispersing fibers and minimizing fioccing thereof adjacentthe outlet of a flow channel or headbox prior to delivery of the stockto the forming surface of a papermaking machine.

These and other objects, features, and advantages of the presentinvention will become readily apparent to those skilled in the art froma consideration of the following detailed description when considered inconjunction with the accompanying drawings illustrating preferredembodiments of the present invention and wherein like reference numeralsand characters refer to like and corresponding parts throughout theseveral views.

On the drawings:

FIGURE 1 is a view in vertical section of a headbox arrangementconstructed in accordance with the principles of the present invention.

FIGURE 1-A is a top view in section of an alternative reject dischargechannel which may be positioned in the region designated A of FIGURE 1.

FIGURE 2 is a view in vertical section illustrating an alternateembodiment of the invention wherein an adjustable nozzle is employed ina headbox consrtucted in accordance with the principles of the presentinvention.

FIGURE 3 is a view in vertical section of a headbox wherein the furnishis supplied to the screen through a curved flow channel.

FIGURE 4 is a view wherein stock is supplied to the flow channelparallel to the outlet thereof.

FIGURE 5 is a top view in elevation of a flow channel arrangement.

FIGURE 6 is a view in vertical section taken along line XIV-XIV of FIG.5.

FIGURE 7 is a view in vertical section of a dual flow headbox whereinthe furnish is supplied to the screen I FIGURE 11 illustratesaverticalsection of a flow channel employing an adjustable screen havingdiiferent size apertures.

FIGURE 12 is a view in vertical section of the device of FIGURE 11illustrating a solid plate section.

As shown on the drawings:

Briefly stated, the present invention involves employment of a screenmember positioned in a headbox or flow channel adjacent the outletthereof through which the stock furnish flows onto a forming surface; Onthe inlet side of the screen, a hydrofoil arrangement carries bars ofgenerally aerodynamic configuration which cooperate with the supply sideof the screen plate to deliver the furnish through apertures formed inthe plate thereby dispersing the fibers immediately prior to theirdelivery to the forming surface and thereby minimizing fioccing thereof.Secondarily, the rotor bars tend to maintain the supply side of thescreen free and prevent lumps or agglomerations from building up on thescreen and clogging the apertures in the screen.

Important aspects of the invention include generally a tangential stockinlet to the interior screen system (as in the case of FIGURES 1 through8) and/ or generally tangential outlet therefrom, (usually through asuitable screen member which affords cross flow and precludes rejectsfrom entering into the stock being fed to the forming surface, as inFIGURES 9 and 10).

As appears in FIGURE 1, the general arrangement of a headboX or flow boxassembly 1B is shown for delivering stock fed through an inlet 2 to anoutlet 3 positioned over a conventional breast roll 5 carrying a formingsurface, such as a Fourdrinier wire 4. The outlet 3 may be provided witha conventional adjustable slice 3a.

The headbox or flow channel assembly 1 includes a front wall 6, rearwall 7, an open or closed top 8, side walls 9, one of which appears inFIGURE 1, and a bottom wall 10. The bottom wall 10 may carry an apron 11and with the tapered wall 12 define a converging flow path to the outlet3.

The stock in the headbox has a free surface level L, maintained by alevel control Set. With a pressure type headbox this would be an orificepermitting a balanced escape of liquid and air. With an open typeheadbox this would be a conventional overflow. Conventional showers 8bsuppress foam and assist in maintaining a clean surface.

Positioned in the headbox adjacent the outlet 3 is a hydrofoilarrangement including a rotor 13 carried by a shaft 14 which isrotatable counterclockwise by means (now shown) which may vary the speedat which the rotor 13 is rotated. It will be noted in FIGURE 1 that therotor is completely submerged below the furnish surface level L.

The rotor appearing in FIGURE 1 carries four more radially extendingarms 154%. Carried at the end of each arm -18 and preferably at an equaldistance from the rotor 13 is a head or foil bar 19-122 of generallyaerodynamic configuration in cross-section. v

A curved screen plate 23 extends the full width of the headbox and isconnected to the wall 12 as at and the bottom wall 10 as at 26. Thescreen 23 is concave as seen from the rotor 13 and is provided with aplurality of apertures 24 through which the furnish is supplied to theoutlet 3. The bars 12-22 are preferably of a length sufficient to sweepadjacent the transverse width of the plate 23 for the effective flow ofthe furnish to the apertures 24.

Each bar 19-22. is provided with a leading edge and a trailing edge anda portion of the outer surface of, the bar adjacent the supply side ofthe screen 23 is curved concave in section as seen from the rotor 13.

The outer surface of each bar 19-22 is positioned inwardly from thesupply side of the screen 23 a small distance so that as each bar passesaround adjacent the inner surface of the screen its leading edge createsa positive pressure wave tending to force the furnish in the spacebetween the screen 23 and outer surface of the bar 1922 through theapertures 24 of the screen and to the outlet 3 of the flow channel orheadbox 1.

The trailing edge of each bar 19-22 develops between the supply side ofthe screen 23 and the outer surface of the trailing edge of each bar awave of reduced pressure, when compared with the pressure conditioncreated between the leading edge of each bar and the screen, which tendsto draw away from the surface of the screen large lumps, particles orfibers which would otherwise tend to remain in place and clog thescreen. The rotation of the hydrofoil arrangement causes these largesize lumps to be drawn downwardly and tangentially outward through aflow channel A defined by an arcuate baffie plate and the end wall 10. Adistributor roll 27 of the conventional perforated type having apertures28 therein is provided for further enhancing fiber distribution anddispersion in the flowing slurry.

A plurality of showers 8b are disposed above the level L of the furnishand a level control outlet 8a is also provided.

In the embodiment appearing in FIGURE 1, the approach of the flow offurnish to the plate 23 is tangentially from the top of the chamberthrough an inlet 36 defined by the screen 23 and an end of an arcuateplate 37. A plate 37a joins with plate 37 to assure streamline flowchannel into the chamber 7a. Once the furnish is introduced into thechamber defined by the hydrofoil and screen plate and arcuate plate 37,and furnish is supplied through the apertures of the screen plate andtailings are exhausted through the outlet A.

FIGURE 1A is a top view in section depicting a preferred alternateconstruction of a reject/recirculation outlet 40a of FIGURE 1 (which maybe used in FIG- URE l at substantially the mouth or peripheral location,indicated at A, of the tangentially aligned outlet slot between theinlet fioor 10 and the wall 30 for flow control). Struts or abutments40b serve to stiffen upper wall 30 and to limit and control flow ofexiting stock through the spaces 46a defined thereby. Similar structureis preferred for reject outlets shown in other modifications herein.

In the arrangement appearing in FIGURE 3 the headbox is constructed sothat the flow channel 66 is defined by an outer wall member 67, agenerally hemicylindrical screen plate 68 and a formed wall member 69.The wall 69 is preferably attached at the screen plate 68 terminus sothat the wall 69 is curved rather than abrupt. The desired curve may beapproximated by an involute developed on the cylinder 68. This is foundadvantageous to across the full width of the chamber.

maintain a square velocity profile, i.e., where instantaneous velocitiesare everywhere equal through a plane perpendicular to the generaldirection of flow in the: channels while in a highly turbulentcondition. In this embodiment, the flow of stock is directed upwardlythrough the inlet 2 and the hydrofoil bars 19 tend to carry the slurryupwardly and around through the apertures formed in the plate 68.Rejects are removed tangentially through the reject outlet 58a which maycomprise a plurality of pipes coextensive with the headbox width and,thus, functionally comparable to the embodiment of FIG- URE 1A. One ofthe advantages of this particular atrangement is that the main flowcomponent is nowhere subjected to abrupt change of direction.

In FIGURE 4, the furnish is supplied tangentially into the top of thechamber defined by the hydrofoil and screen plate 68 and rejects aretaken off tangentially through the outlet 58a having a lateral leg 58b.The screened slurry flows through a converging flow channel 70 whichalso has an insert 6 9 as previously described, to the outlet 5 thereofand to, the forming wire 4.

It will be observed that the furnish is introduced in one direction andsupplied to the forming wire in a diametrically opposite direction,without abrupt change of direction. This modification is particularlyuseful for the well known secondary headbox on Fourdrinier papermachines.

In FIGURE 2, there is shown an arcuate delloccing chamber 71 to whichthe furnish is supplied tangentially through a channel 72 defined by thetop guiding wall 73 and an arcuate solid plate member 74 which extendsThe furnish is supplied through a screen member 75 into a convergingflow channel 76 defined by a top wall 77 and a bottom wall 78. The flowchannel 76 extends the full width of the forming wire 4 and thedeflocced furnish flows through the outlet 79 onto the forming wire. Tovary the height of the outlet, the top wall 77 is pivoted at 80 to thetop wall 73.

The tailings and rejects are removed tangentially through an opening 81into a chamber 31a feeding into a cross flow conduit 81b indicateddiagrammatically as feeding to a downwardly directed outlet 40a. Thechamber is defined by the bottom wall 10 land a section 74a of thecurved wall 74. A side wall 83 cooperates with the end wall 73 to definethe flow path 72.

In the embodiment appearing in FIGURE 5 a compact drum type flow vessel,generally indicated by the numeralis disclosed, which can be made topivot around the horizontal axis (FIGURE 6), which is also the axis ofthe rotating hydrofoil assembly. The combination of the translatorymovements (laterally and vertically, means not shown) with the rotarymovement permits the exact positioning of the issuing jet on the formingwire. The flow vessel '95 consists of a central chamber '96 containing ahydrofoil arrangement therein which includes an enlarged rotor supportedin the bearing housings. Means (not shown) are provided for driving theaxle of rotor 97 and means are provided for pivoting the flow vessel 95about the horizontal axis. This arrangement is of particular advantagefor pressure forming devices where the nozzel direction requires veryexacting adjustments.

The rotor 97 carries the hydrofoil arms 15 and bars 19 which by means ofpulsation permit the movement of furnish through the apertures 24 in thescreen plate 23. From the channel 106, the defiocculated furnish flowsimmediately through the outlet 3 onto the forming wire 5.

The furnish is introduced int-o the top portion of the chamber 96through a flow channel 1tl7 which is sized to the chamber 96. Thefurnish is introduced into the channel 107 from an annular chamber 1&8which may be considered similar to the cross flow distributor of wellknown construction. The chamber 108 is defined by hemicylindricalhousing 109 and a generally concentric inner pipe 110 which communicateswith an inlet conduit 111 and extends preferably the full width of thehousin 109.

The conduit or tubing 110 is provided with a plurality of apertures 112,one of which is shown in FIGURE 6. These are so designed to provide aneven pressure distribution in the annular chamber 108. It will beobserved that the apertures 112 are formed in the pipe 110 on the sidethereof opposite the flow channel 107. In this man,- ner the force ofthe jets issuing from the perforations is dampened and most of theenergy reconverted into pressure. The fibers are distributed to someextent with the furnish flowing through the apertures 112 and passing asindicated by the arrows, for How in two directions. Thus, the furnish isseparated into two flow paths and recombines or merges in the channel107 thereby further enhancing fiber distribution in the slurry prior todelivery thereof to chamber 96.

In the FIGURE 7 is illustrated a dual flow headbox assembly thatincludes two sections 115 and 116 which receive stock from a pluralityof inlet lines 117 and 118, respectively, and deliver the stock to adouble slice lip or nozzle 119. Each of the sections 115 and 116includes two solid arcuate wall sections 120 and 121 which form the twolips 122 and 123 at one end and are in open communication with the inletlines from a suitable distributor at their other ends 124 and 125.

Within the headbox assembly are fixed two solid arcuate members 126 and127 which join at the center to form a common wall 128. Two arcuateextensions 129 and 130 of the two members 126 and 127, respectively,converge at the point 133 and form, with the arcuate outer members 120and 121, two flow channels 131 and 132. A plurality of braces 134 arefastened to the members 126, 127, 129 and 130 for support.

Mounted with the two sections 115 and 116 are two hemicylindrical screenplates 135 and 136 which have a plurality of apertures 137 and 138formed in them. Concentrically mounted within each of the two screenplates 135 and 136 are rotors 139 and 140 which are carried by twoshafts 141 and 142, respectively. Each of the rotors 139 and 140 carriesradially extending arms 143 and 144, respectively, which support aplurality of heads or foil bars 145 and 146. Again, the "bars 145 and146 are. mounted at equal distances from the rotors 139 and 140 andsweep adjacent the transverse width of the plates 13.; and 136 in orderto induce the flow of the stock through the apertures 137 and 138.

The rejects or tailings are removed from the two sections 115 and 116through a plurality of reject lines 147 and 148.

The combinations possible with this type of arrange-- ment are numerous.The following are some of the improvements that are obtainable overpresent head boxes: Better formation, better strength in cross-section,better drainage control at high speeds, and lower loss of fillers in thewhitewater.

The principle incorporated is based on the non-mixing of streams whenflowing through a converging section. The forming of the sheet takesplace in the short section available at the discharge of the orifice ornozzle. The following are some of the jet combinations that arepossible:

(1) upper jet with short average fiber distribution and lower jet withlong fibers; (2) upper jet with low consistency and lower jet with highconsistency; (3) upper jet of higher grade stock (liner) and lower jetof lower grade stock; (4) upper jet at wire speed or slower and lowerjet at wire speed; and (5) upper jet with filler and lower jet withoutadditives.

A further possible application of the double jet prin ciple lies in thedouble wire forming of paper.

In FIGURE 8 is illustrated an alternate type of dual nozzle for thisapparatus. This apparatus includes an upper slice lip 150' that isfastened to a pivotally mounted shaft 151 and a lower slice lip 152'that is fastened to a pivotally mounted shaft 153. These two lips 150'and 152' are connected to two actuator rods 154' and 155' which vary thevertical position of the two lips 150' and 152'. These two rods 154' and155 may-be connected to a suitable motor (not shown) such as an air orhydraulic motor. 7

A member 155 is mounted between the two lips 150 and 152' on a rotatableshaft 156'. This member converges to a point at 157' which extendsbetween the two lips 150' and 152. the member 155' through which watercan be injected for lubrication purposes.

It is apparent that by moving the rods 154 and 155', the two lips and152' can be made to pivot around the axes of the shafts 151' and 153 inorder to vary the width of the stock outlet 159' or to change the angleat which the stock is discharged. Further, the position of the membercan be varied in order to give a different percentage of the stockcoming from the two sections.

With the apparatus of the present invention, an even flow in thetransverse and longitudinal directions of the furnish are created bymaintaining average velocities essentially the same in the flow offurnish and the elimination of cross flows whether of transient orperiodic origin.

The type of headbox or flow vessel employed is not considered critical.The operating features of the hydrofoil screen arrangement should besuch that the hydrofoil rotates at speeds, for example within the rangefrom about 30 to about 60 fps. to provide the intensity of pulsesrequired to maintain the plates open and the frequency of operation willdepend largely upon the type of screen perforations and the consistencyof the stock. Excellent results are obtained where the frequency is notless than 20 c.p.s. at machine speeds of 1,000 f.p.m. In this manner,'the longitudinal basis weight variations are minimized. In addition,the distance or clearance of the hydrofoil bars from the screen may bevaried depending upon the intensity of the pulses required. Excellentresults are obtained where the clearance between the hydrofoil bar andscreen is within the range of from about .060" to about 1.00" andaclearance of about A" has produced satisfactory results. The hydrofoilbar should also be designed to oifer a rounded surface of a thicknessnot less than /2" on the leading edge adjacent the screen. The channelbetween the screen and bar created by the hydrofoil and the screenplates should be established in such a manner that the angle of attackof the hydrofoil leading edge does not exceed a critical divergenceangle formed by the trailing edge of the bar and the curvature of theplate. Experimentation indicates that this angle should be less than 14.

Preferably the furnish entering the chamber inwhich the hydrofoil barsare located should be introduced preferably in a direction of rotationof the hydrofoil bars to minimize the possibility of creation of largeturbulence and the dissipation of energy into heat. The power requiredfor the assembly will be reduced substantially if the furnish is fedtangentially into the chamber in which the hydrofoil bars are rotatingat velocities within the range of from about 10 to about 15 feet persecond. Experimentation has indicated that the power requirements torotate the hydrofoil bars in the same direction as introduction of theflow of furnish will be approximately 50% less than in the case wherethe hydrofoil bars are rotating in a direction opposite to the directionof flow of the furnish into the chamber.

It will be appreciated that the intensity of pulsation and frequency ofthe bar and screen arrangement will depend largely upon the consistencyof the furnish being defiocced. The higher the stock consistency, thegreater the amount of energy required to obtain the same flow throughthe screen plate, other conditions being identical. The power requiredto drive the rotating hydrofoil members will depend greatly on the typeof structural supports assigned to carry the hydrofoil structures. Inaddition,

At least two slots 158' are formed in- Reynolds number, N within therange of from about X10 to about 5x10 The Reynolds number is adimensionless ratio equal to a characteristic length L, in this case thechord of the hydrofoil, multiplied by the linear velocity of V of thefoil, divided by the viscosity '1 of the fluid The screen plateperforation size will depend upon the type of fibers in the furnish andthe consistency of the furnish. It will be observed, however, thatperforations to times smaller than the perforations in the presentrectifier rolls will be possible.

A thin plate may be employed and the type of mechanical construction andsupport for such plate will depend upon factors such as furnish velocityand consistency. Thus, the sizeof the plate or cross-sectional thicknessmay be determined in conventional manner.

The actual configuration of the hydrofoil bar in crosssection may be anyconfiguration so long as the pulsation effect is created adjacent thescreen and the leading edge supplied the furnish through the screen andthe trailing edge cleans the supply side of the screen.

Thus, the hydrofoil bar in crosssection may have any aerodynamicconfiguration, the velocity of the foils and the number of the foilsemployed will depend upon intensity of pulsation required, which in turndepends upon the type of furnish, number of apertures in the screenplate, size of the apertures and the like. The velocity of the foil barsis independent of the entering velocity of furnish and the exit velocitythrough the apertures of the screen plate depend upon the number ofapertures, size of the apertures and the like. The position of the barsrelative to the screen depends upon these factors also, but in general,it will be observed that the bars located relative to the screen tocreate a pressure on the leading edge of the bar to force the furnishthrough the apertures and a reduced pressure at the trailing edge of thebar to clean the screen.

Vibrating means (not shown) may also be employed for vibrating thescreen to assist in the cleaning effect. The hydrofoils operatepreferably completely submerged in the slurry and the apertures in thescreen may be slots, perforations and the like.

It will be noted that one characteristic of the views of FIGURES 1through 8 is that these views show the stock feed to the interior screenas being generally tangential in character. In contrast it will be seenhereinafter that the stock feed to the embodiments of FIGURES 9 and 10involve cross-machine stock feed; but all of these embodiments involvewithdrawal of rejects along a generally tangential slot (or itsequivalent) from the screen, at an open portion thereof along agenerally tangential region.

=Briefiy stated, the present invention of FIGURES 9 and 10 involvesemployment of a screen cylinder positioned in a headbox or flow channeladjacent the outlet thereof through which stock furnish flows onto aforming surface of a papermaking machine. On the inlet side of thescreen, a hydrofoil arrangement carries bars of generally aerodynamicconfiguration which cooperate with the supply side of the screencylinder to deliver the furnish flowing centrally in a cross-machinedirection through apertures formed in the cylinder thereby dispersingthe fibers immediately prior to their delivery to the forming surfaceand thereby minimizing floccing thereof. secondarily, the rotor barstend to maintain the supply side of the screen free from lumps and alsoprevents lumps or agglomerations and the like from building up on thescreen cylinder and clogging the apertures thereof.

As appears in FIGURE 9, the general arrangement of a headbox or flowassembly, generally indicated by the numeral 114 is shown for deliveringslurry of furnish fed through cross-machine inlet 115 to an oppositecrossmachine outlet 116 positioned over a conventional breast roll 117carrying a forming surface, such as a Fourdrinier wire 118. The outlet116 may be provided with a conventional adjustable slice' (not shown),but is equipped for cross-machine recirculation of the stock.

The headbox or flow channel assembly 11d includes a downwardly directedtop wall 1119 which converges with the bottom wall v116 to define theoutlet 116. The assembly 114 is provided with an arcuate end wallportion 111 which joins the bottom wall 110. A generally tangentialcross-machine slot i also provided between the walls 141 and 14-2 whichslot 143 receives rejects and withdraws the same in a cross-machinedirection via a cross-machine header 144 at the forward end thereof. Tocomplete the headbox assembly, two side walls .112, one of which isshown in FIGURE 10, run parallel to each other on each side of the walls109 and .110. The headbox assembly is in a cross-machine directionsize-d to the effective forming surface of the wire 11% and the bottomwall may carry an apron (not shown) adjacent the outlet.

Positioned in the headbox is a hydrofoil arrangement including a rotor113 carried by a shaft 124 which is rotatable by means on bearings 114awhich may also vary the speed at which the rotor 13 is rotated. Therotor 113 carries radial arms 119a, etc., 113a, etc. Carried at the endof each of the arms 113a, etc., and preferably these arms or foils 119a,etc. are at equal distances from the rotor 113. Each such bar 119a is ahead or hydrofoil bar 119a, etc. of general aerodynamic configurationcross-section which extends lengthwise of a cylindrical housing 111.

The cylindrical housing 111 is provided with a peripheral screen portion151 within the periphery of a portion of the housing '111,and 110 and issupported in the assembly 114 by the side walls 112. With the slottedrotor 113, the concentric slotted stationary cylinder 53 define across-machine cylindrical stock channel from 115416. The chamber orchannel -116 may be of any crosssectional width depending upon the sizeand configuration of the slotted rotor 113 and stationary member 153,which has slots 154 in registry with the smaller elongated slots 155 innon-rotary cylinder 153.

The bars 119a, etc. are preferably of a length sufficient to sweepadjacent the transverse width of the cylindrical housingjll foreffective flow of the furnish through the screened apertures 151therein.

Each of the bars 119a, etc. has a leading edge, atrailing edge, and anouter surface (all as hereinbefore shown). This outer surface isdisposed closely adjacent the inner surface of the cylinder 111 and itsscreen 151 and a small space .127 is defined between the inner surfaceof the cylinder 11-1 and its screen 151 and the outer surface of each ofthe bars 119a, etc.

When the rotor 113 and the eight bars 11%, etc. are rotating at properspeeds, each bar creates a momentary pressure variation or pulse in thefurnish. A pressure wave travels around the screen 151 at the speed oftravel of the bars 119a, etc., and each point of the cylinder screen iseffected by each pressure wave only instantaneously.

The type, intensity and duration of the pressure waves obtained dependson the position of the foils in relation to the cylinder, the length ofthe foils, and their linear speed. In general they consist of anincrease above the average pressure in the chamber as the leading edgeof a foil approaches a reference point on the cylinder and a decrease inpressure starting at'the point of minimum clearance between the surface(indicated at 126 for the foil 11%) and the cylinder screen 151. Thisresults in a very effective and localized pulse which, by reversing thedirection of flow, permits the dislodging of fibrous lumps or otherundesirable particles which, otherwise, may remain lodged in theapertures of the screen portion 151 and clog the screen cylinder.

The rotation, clockwise or counterclockwise, of the bars 110a, etc.causes the undesirable lumps or particles to be drawn downwardly and outof the head-box through a generally tangential outlet opening 143between the walls 141 and 142. The outlet opening 143 communicates withthe cross-machine chamber 144 and carries these large size lumps andother particles through such a discharge conduit 144 in a cross-machinedirection.

The entire headbox system is maintained under pressure during operationand is filled with stock. The stock afiter passing through the screenapertures in the screen portion 131 flows in a generally tangentialdirection toward the outlet 116 between the walls 109 and 110.

It will thus be appreciated that the rejects are removed generallytangentially at the forward end of the rotating foils and the refined,screened stock is also processed through a screen (e.g. 151, 23, etc.)in a generally radial direction initially but in the case of the unit ofFIG- URES 9 and this refined stock flow is ultimately converted into agenerally tangential flow (with respect to the rotating foils of theunit).

It will be understood that modifications and variations may be efiectedwithout departing from the scope of the novel concepts of the presentinvention.

Referring to FIGURES L1 and 12, it will be seen that these figurescorrespond respectively to FIGURES 5 and 6 of our aforesaid previousapplication Serial No. 141,270 (now abandoned) although the referencenumerals used herein are the same as those previously usedexcept thatthey are in the 200 series. In the headbox flow channel arrangement 201Dappearing in FIGURE 11, the screen plate 223 is provided with anextension 245 of smaller cross sectional thickness than the section 223with apertures 245a of smaller dimension than the apertures 224. Thescreen sections 223 and 245 are rotatable clockwise to the positionshown by the dotted lines for positioning the screen section 245adjacent the outlet 203 of the flow channel arrangement. Arms 246provide support and carry the plate sections 223 and 245. The arms 246are carried by an adjustable stationary section (not shown) on the rotorwhich is movable to position the screen as required or an adjustablesleeve (not shown) may be provided for carrying the arms 246.

The arrangement 201D employing two screen plates of different types,which may be used alternately if the paper machine has a varyingrequirement in flow or type of fiber used, permits the use also of ablank unperforated plate 247, as appears in FIGURE 12, to act as a valveat the slice 203 and block flow to the wire 204. In this arrangement theblank section 247 provides means for defining a pair of chambers 247aand 2471: in the headbox or flow channel arrangement 201E of FIGURE 6,with the plate 247 in the position shown. The wall 212 and bottom wall210 define the chamber By closing the adjustable slice 203a so that itblocks the outlet 203, the chamber 247a is in condition to be cleanedwithout requiring the complete termination of flow of the furnish to thehead box chamber 24711 or complete shutdown of the forming wire and thepaper making machine. An inlet (not shown) to chamber 247a may beprovided as may be an outlet 2470 through which a fluid may be tflowedfor cleaning the chamber 247a. The furnish in the chamber 247b may berecirculated through means (not shown) communicating with the channel230 for returning the furnish to the source thereof. Similarly, thechannel 247d may be cleaned by flushing with a cleaning .fiuidintroduced 10 through the inlet 202 which discharges through the channel230. The blank member 247 when positioned as shown in FIGURE 12 willprevent flow of the cleaning fluid or stock onto the forming wire 204from the chamber 24717.

We claim as our invention:

1. In apparatus adapted for minimizing floccing and for increasingdispersion of fibers in papermaking furnish prior to delivery thereof toa web forming means of a papermaking machine comprising a fiow vesseldefining a furnish flow path, an inlet to .the flow vessel forintroduction of furnish under pressure along the flow path, an outlet ofthe vessel for delivering furnish to web forming means of a papermakingmachine, an arcuately shaped plate in the vessel adjacent the outlet andextending transversely to the direction of flow of furnish, meansdefining perforations in a portion of the plate positioned for flow offurnish to the outlet, a reject outlet for discharge of tailings, lumpsand agglomerations from the vessel, and a rota-table member of generallyaerodynamic configuration in cross-section disposed in the vesselbetween said arcuate plate and the inlet to the flow vessel and in theflow path of the tfurnish for urging furnish toward and away from theperforated portion ofthe plate, the improvement comprising meansdefining a transverse inlet slot at one edge of the plate extending thefull width of the plate positioned for tangentially introducing thefurnish to the supply side of the plate.

2. In apparatus adapted for minimizing floccing and for increasingdispersion of fibers in paper-making furnish prior to delivery thereofto a web forming means of a papermaking machine comprising a flow vesseldefining a furnish flow path, an inlet .to the flow vessel forintroduction of furnish under pressure along the flow path, an outlet tothe vessel for delivering furnish to web forming means of a paper makingmachine, an arcuately shaped plate in the vessel adjacent the outlet andextending transversely to the direction of flow of furnish, meansdefining perforations in a portion of the plate positioned for flow offurnish to the outlet, a reject outlet for discharge of tailings, lumpsand agglomerations from the vessel, and a rotatable member of generallyaerodynamic configuration in'cross-section disposed in the vesselbetween said arcuate plate and the inlet to the flow vessel and in theflow path of the furnish for urging furnish toward and away from theperforated portion of the plate, the improvement comprising meansdefining a transverse inlet slot at one edge of the plate extend-ing thefull width of the plate positioned for tangentially introducing thefurnish to the supply side of the plate, said means defining thetransverse inlet slot including guide wall means aiming .the furnishflow path tangentially. t

3. In apparatus adapted for minimizing floccing and for increasingdispersion of fibers in papermaking furnish prior to delivery thereof toa web forming means of a papermaking machine comprising a flow vesseldefining a furnish flow path, an inlet to the flow vessel forintroduction of furnish under pressure along the flow path, an outlet to.the vessel for delivering furnish to web ,forming means of apapermaking machine, an arcuately shaped plate in the vessel adjacentthe outlet and extending transversely to the direction of flow offurnish, means defining perforations in a portion of the platepositioned for flow of furnish to the outlet, a reject outlet fordischarge of tailings, lumps and agglomerations from the vessel, and arotatable member of generally aerodynamic configuration in cross-sectiondisposed in the vessel between said arcuate plate and the inlet to theflow vessel and in the flow path of the furnish for urging furnishtoward and away from the perforated portion of the plate, theimprovement comprising means defining a transverse inlet slot at oneedge of the plate extending the full width of the plate positioned fortangentially introducing the furnish to the supply side of the plate,and means defining a transverse reject fiow path, separate 1 1 and apartfrom the aforesaid transverse inlet slot, and extending the full widthof the plate.

4. In apparatus adapted for minimizing floccing and for increasingdispersion of fibers in papermaking furnish prior to delivery thereof toa web forming means of a papermaking machine comprising a flow vesseldefining a furnish flow path, an inlet to the flow vessel forintroduction of furnish under pressure along the flow path, an outlet tothe vessel for delivering furnish to web forming means of a papermakingmachine, an arcuately shaped plate in the vessel adjacent the outlet andextending transversely to the direction of flow of furnish, meansdefining perforations in a portion of the plate positioned for flow offurnish to the outlet, a reject outlet for discharge of tailings, lumpsand agglomerations from the vessel, and a rotatable member of generallyaerodynamic configuration in cross-section disposed in the vesselbetween said arcuate plate and the inlet to the flow vessel and in theflow path of the furnish for urging furnish toward and away from theperforated portion of the plate, the improvement comprising meansdefining a transverse inlet slot at one edge of the plate extending thefull width of the plate positioned for tangentially introducing thefurnish to the supply side of the plate, said means defining thetransverse inlet slot including guide wall means aiming the furnish flowpath tangentially, and means defining a transverse reject fiow path,separate and apart from the aforesaid transverse inlet slot, andextending the full width of the plate, said reject flow pathmeansincluding guide wall means defining a transverse reject slot aiming thereject flow path tangentially away from said arcuate plate.

. 5. In apparatus adapted for minimizing floccing and for increasingdispersion of fibers in papermaking furnish prior to delivery thereof toa web forming means of a papermaking machine comprising a flow vesseldefining a furnish flow path, an inlet to the flow vessel forintroduction of furnish under pressure along the flow path, an outlet tothe vessel vfor delivering furnish to web' forming means of apapermaking machine, an arcuately shaped plate in the vessel adjacentthe outlet and extending transversely to the direction of flow offurnish, means defining perforations in a portion of the platepositioned for flow of furnish to the outlet, a reject outlet fordischarge of tailings, lumps and agglomerations from the vessel, and arotatable mem'ber adapted to rotate in a given direction, said memberbeing of generally aerodynamic configuration in cross-section disposedin the vessel between said arcuate plate and the inlet to the flowvessel and in the flow path of the furnish for urging furnish toward andaway from the perforated portion of the plate, the improvementcomprising means defining a transverse inlet slot at one edge of theplate extending the full width of the plate positioned for tangentiallyintroducing the furnish to the supply side of the plate, said inlet slotbeing aimed in the aforesaid given direction, and means defining atransverse reject flow path, separate and apart from the aforesaidtransverse inlet slot, and extending the full width of the plate, theaforesaid transverse inlet slot being positioned above the aforesaidtransverse outlet means, and the aforesaid rotatable member ofaerodynamic configuration effecting pulse-feed of furnish to theperforated plate portion.

6. In apparatus adapted for minimizing floccing and for increasingdispersion of fibers in papermaking furnish prior to delivery thereof toa web forming means of a papermaking machine comprising a flow vesseldefining a furnish flow path, an inlet to the flow vessel forintroduction of furnish under pressure, an outlet to the vessel fordelivering furnish to web forming means of a papermaking machine, anarcuately shaped plate in the vessel adjacent the outlet and extendingtransversely to the direction of flow of furnish, means definingperforations 12 in a portion of the plate positioned for flow of furnishto the outlet, a reject outlet for discharge of tailings, lumps andagglomerations from the vessel, and a rotatable member of generallyaerodynamic configuration in cross-section disposed in the vesselbetween said arcuate plate and the inlet to the flow vessel and in theHow path of the furnish for urging furnish toward and away from theperforated portion of the plate, the improvement comprising meansdefining a transversely extending slotted inlet extending the full widthof the plate positioned for introducing the furnish to the supply sideof the plate, and means defining a transverse reject flow path, separateand apart from the aforesaid transverse inlet, and extending the fullwidth of the plate, said transversely extended inlet receiving furnishflowing transversely from at least one end thereof inwardly and thenconverting the transverse flow to flow through the slots thereofgenerally aligned in planes perpendicular to the initial transverse flowdirection and toward the rotatable member.

7. In apparatus adapted for minimizing floccing and for increasingdispersion of fibers in papermaking furnish prior to delivery thereof toa web forming means of a papermaking machine comprising a flow vesseldefining a furnish flow path, an inlet to the flow vessel forintroduction of furnish under pressure, an outlet to the vessel fordelivering furnish to web forming means of a papermaking machine, anarcuately shaped plate in the vessel adjacent the outlet and extendingtransversely to the direction of flow of furnish, means definingperforations in a portion of the plate positioned for flow of furnish tothe outlet, a reject outlet for discharge of tailings, lumps andagglomerations from the vessel, and a rotatable member of generallyaerodynamic configuration in cross-section disposed in the vesselbetween said arcuate plate and the inlet to the flow vessel and in theflow path of the furnish for urging furnish toward and away from theperforated portion of the plate, the improvement comprising meansdefining a transversely extending slotted inlet extending the full widthof the plate positioned for introducing the furnish to thesupply side ofthe plate, and means defining a transverse reject flow path, separateand apart from the aforesaid transverse inlet, and extending the fullwidth of the plate, said transversely extending slotted inlet mounting arotary slotted member carrying the aforesaid member of generallyaerodynamic configuration, said slotted inlet receiving internallyfurnish under pressure from at least one end thereof to divert thefurnish from an initial transverse flow direction outwardly through theslots of the inlet and the rotary slotted member carried thereby andinto an annular region confined by said plate and the vessel wallscarrying said plate;

8. An apparatus adapted for minimizing floccing and for increasingdispersion of fibers in paper making furnish prior to delivery thereofto a web forming means of a paper making machine comprising a flowvessel defining a furnish flow path, an inlet to the flow vessel forintroduction of furnish under pressure along the flow path, an outlet tothe vessel for delivering furnish to web forming means of a paper makingmachine, an arcuately shaped plate having two portions in the vesseladjacent the outlet and extending transversely to the direction of flowof furnish, means defining perforations in one portion of the platepositioned for flow of furnish to the outlet, a reject outlet fordischarge of tailings, lumps, and agglomerations from the vessel, and arotatable member of generally aerodynamic configuration in cross-sectiondisposed in the vessel between said 'arcuate plate and the inlet to theflow vessel and in the flow path of the furnish for urging furnishtoward and away from the perforated portion of the plate, theimprovement wherein the other portion of said plate is imperforate, andmeans defining a generally transverse open slot adjacent saidimperforate portion for said rotatable members to tangentially drivetailings and furnish incapable of entering said perforations in agenerally tangential direction away from said one portion of the plateand into the reject outlet.

References Cited by the Examiner UNITED STATES PATENTS 1/1961 Baxter162348 8/1962 Baxter 162-339

1. IN APPARATUS ADAPTED FRO MINIMIZING FLOCCING AND FOR INCREASINGDISPERSION OF FIBERS IN PAPERMAKING FURNISH PRIOR TO DELIVERY THEREOF TOA WEB FORMING MEANS OF A PAPERMAKING MACHINE COMPRISING A FLOW VESSELDEFINING A FURNISH FLOW PATH, AN INLET TO THE FLOW VESSEL FORINTRODUCTION OF FURNISH UNDER PRESSURE ALONG THE FLOW PATH, AN OUTLET OFTHE VESSEL FOR DELIVERING FURNISH TO WEB FORMING MEANS OF A PAPERMAKINGMACHINE, AN ARCUALTELY SHAPED PLATE IN THE VESSEL ADAJCENT THE OUTLETAND EXTENDING TRANSVERSELY TO THE DIRECTION OF FLOW OF FURNISH, MEANSDEFINING PERFORATIONS IN A PORTION OF THE PLATE POSITIONED FOR FLOW OFFURNISH TO THE OUTLET, A REJECT OUTLET FOR DISCHARGE OF TAILINGS, LUMPSAND AGGLOMERATIONS FROM THE VESSEL, AND A ROTATABLE MEMBER OF GENERALLYAERODYNAMIC CONFIGURATION IN CROSS-SECTION DISPOSED IN THE VESSELBETWEEN SAID ARCUATE PLATE AND THE INLET TO THE FLOW VESSEL AND IN THEFLOW PATH OF THE FURNISHED FOR URGING FURNISH TOWARD AND AWAY FROM THEPERFORATED PORTION OF THE PLATE, THE IMPROVEMENT COMPRISING MEANSDEFINING A TRANSVERSE INLET SLOT AT ONE EDGE OF THE PLATE EXTENDING THEFULL WIDTH OF THE PLATE POSITIONED FOR TANGENTIALLY INTRODUCTING THEFURNISHED TO THE SUPPLY SIDE OF THE PLATE.